In accordance with recent varieties of consumer's needs, small-diameter compact discs (hereinafter called CD) of 8 cm standard have widely been distributed in addition to those of 12 cm standard. Therefore, CD players are required to be available for discs of large and small two sizes, small-scaled, simply arranged and excellent in operability.
There is a disc loading mechanism shown in FIG. 9 configured to automatically convey a disc and position it on a turn table in a CD player for discs of the existing 12 cm standard.
In the mechanism of FIG. 9, a driving roller 24 is disposed in a side of the turn table 22 of the CD player 21 nearer to a disc insertion aperture 23 (lower side in the drawing). As shown in FIG. 10, the driving roller 24 and a support member 25 opposed thereto sandwich the inserted disc 26, and the driving roller 24 is rotated to convey the disc 26 until the front outer edge of the disc 26 engages positioning projections 27 provided in two different front positions (upper positions in the drawing) in the convey path. Thus the disc 26 is set in a proper position on the turn table, with the center hole 26a of the disc 26 engaging with the center of the turn table.
The disc loading mechanism of FIG. 9, however, can accept large-diameter discs of 12 cm standard alone. Therefore, in order to use a small-diameter disc of 8 cm standard in such a 12 cm standard player, an adapter is required to conform the 8 cm disc with the 12 cm standard.
The above-indicated disadvantage is not limited to CD players alone, but is common to various disc players, in general, in which the use of discs of large and small two sizes is desired.
Thus the existing disc loading mechanism is poor in operability because of its unavailability for discs of both large and small sizes unless an adapter is used.